Table 2 ‐ 6mm and 6.5mm Cartridge Water Capacity (gn water to the case‐mouth) 6mm
6.5mm Cartridge 6BR 6PPC 6BRX/Dasher 6mm Swiss Match 6‐6.5X47 Lapua Tubb 6XC H2O (gn) 38.6gn ~33.0gn 41.5gn 45.9gn ~49.0gn 49.7gn 243WSSM/243 Win 54.1gn 6‐284 Norma ~67.0gn Index 100 85 110 119 126 128 140 173
of thousandths of an inch, but it’s enough to see you have slightly hard chambering of the loaded round and very hard extraction of its fired case – the soft-faced mallet on the bolt-handle root plus cleaning-rod needed down the bore! So, ensure your gunsmith uses a reamer that is ‘minimum Lapua brass’ specification. There are cures if you suffer this starting with a return to the gunsmith to have him hone the rear of the chamber out marginally. Alternatively, buy Norma cases, or rather cheaper Redding’s 6BR small-base body die part number 74317 that reduces the lower case body diameter marginally. You only need to use it every five firings or so.
Irrespective of maker, the 0.473 inch dia. case-head and thick web see lots of metal around the small rifle primer dimensioned primer pocket, which adds to
Table 3 ‐ 6BR v .Smaller 6.5mm Cartridge External Ballistics Cartridge/Bullet
MV 6BR / 105gn Berger VLD 6Dasher / 105gn Berger VLD 6.5X47L / 140gn Berger VLD 2,800 2,950 2,800 .260 Rem / 140gn Berger VLD 2,900 * Free recoil energy in a 13lb rifle
D600(1) / D1,000(1) = Wind drift to the nearest inch for 10 mph true (90‐degree) crosswind. D600(2) / D1,000(2) = Wind drift to the nearest inch for a simulated 5mph change in a quartering (4 o’clock) wind.
Target Shooter 63 Recoil* 4.7ft/lb 5.6ft/lb 8.7ft/lb 9.8ft/lb V600 1,865 1,984 1,976 2,057 26” 24” 22” 21” D600 (1) D600(2) 11” 10” 9” 9” V1,000 1,347 1,449 1,509 1,580 D1,000(1) 84” 77” 69” 65” D1,000(2) 36” 33” 30” 28”
strength and case-life. There is therefore a tendency to load this cartridge up very heavily indeed - to well above its 58,740 psi CIP PMax. One has to be wary of some loads bandied about by shooters and available on the internet that see MVs well over 2,900 fps quoted for 105 grain bullets. Next month, I’ll look at tools and bullets and ask the QuickLOAD PC internal ballistics program for powder recommendations to see what propellants might suit the cartridge, also noting some ‘standard recipes’ for those who want good results the easy and quick way.
Cartridge 6.5X47mm Lapua H2 O (gn) 49.1gn 6.5mm HDY Crdmoor 52.2gn .260 Rem 6.5X55mm 6.5X55mm AI 6.5‐284 Norma 54.5gn 58.6gn ~62.0gn ~67.0gn Index 100 106 111 119 126 136
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